In this section, Plantinga responds to Tooley’s response to his (Plantinga’s) opening statement. Got it? Obviously, we’re deep in the dialectic at this point. Plantinga focuses on two issues. First, he argues that Tooley has not adequately addressed his complaint that material beings cannot think. Second, he takes issue with Tooley’s response to the evolutionary argument against naturalism.
The Possibility of Thoughtbots
Recall that Plantinga claimed, “we can see on reflection, just as Leibniz suggested, that thought can’t arise from the interaction of the parts of a material object” (218). Tooley tried to explain how a material being could think by trying to explain how a material being such as a robot could have experiences and how those experiences could serve as the basis of thought if the experiences stand in the right sorts of causal relationships to behavior.
Recall that Tooley argued that things other than immaterial minds can have beliefs. Tooley believes it is possible for there to be a robot, Robbie, that has “internal, purely physical states [that] causally give rise to qualia” (202). In defense, he notes:
Well, human brain states causally give rise to sensations and experiences, so it is not easy to see how it could be logically impossible for electronic circuitry to do the same.
Next, Tooley goes on to describe how these qualitative states might serve as the building blocks, as it were, of belief. (See 203-4).
Plantinga, however, will have none of this. The issue, he says, is not a matter of how there could be physical causes of experiences and belief. The dualist can say (and has said) that there can be physical causes of experiences and belief when those physical causes have effects on the immaterial mind. The issue is how a material being without any immaterial soul or mind could have the qualia that serve as the building blocks from which a mind is built in accordance with Tooley’s specifications (221).
Now, Tooley anticipated this objection (as Plantinga notes on 222) and cites as evidence for the claim that material beings can think the example of non-human animals that can think, experience, feel, desire, intend, act, etc… Plantinga believes that there are NHA’s that have mental lives, but “fails to see the source of his presumption that they don’t have immaterial minds” (223). I think this reply is interesting, especially in light of Plantinga’s earlier remarks concerning evolution and immaterial souls. He notes (rightly) that it’s implausible to think that any of the physical changes that take place that lead to new forms of life will lead to the evolution of an immaterial self or soul (33). But, if the alternative view is that at some point in evolutionary development there are NHA’s that receive souls from some supernatural source, I can’t think of any reason why a supernatural entity would dole out souls to those and just those NHA’s we typically think have minds. I think there might be an interesting issue here. What justification is there for an immaterialist about minds to claim that NHA’s have minds if minds only result from some sort of supernatural intervention and the doling out of souls?
I think it’s interesting to note that Plantinga does not seem to respond to Tooley’s response to the claim that we can “just see” that material things cannot think (195-6). While I think it’s heroic for Tooley to try to show how a material being might have a mind, I think it’s sufficient for his purposes to have called into question the claim to be able to “see” that materialism about the mental is false. It would be nice to know why Plantinga thought that Tooley’s response was inadequate because I take it that many, if not most, materialists about the mental adopt a kind of aposteriori materialist view on which there is no way to “see” one way or the other whether mental powers, properties, etc… require anything beyond certain material things.
We’ve discussed the EEAN previously. Tooley, you’ll recall, offered two important responses to the EEAN. First, he denied the following claim, which seems crucial to Plantinga’s argument:
(A1) If P(R/N) is low or inscrutable, the naturalist has a defeater for each of her beliefs, the belief in naturalism included.
This seems to follow from a more general principle of defeat, which is that you have a defeater for your background beliefs if the probability of R/background beliefs is either low or inscrutable. The problem, Tooley claims, is that nothing of epistemic importance follows from the fact that P(R/background beliefs) is inscrutable. Hence, nothing of epistemic importance follows from the fact that P(R/N) is either low or inscrutable.
To this, Plantinga responds as follows:
Tooley asks us to consider an ordinary person who “initially believes that his cognitive faculties are reliable, but who has no idea what produced those faculties, or how probable it is, relative to the totality, T, of other things he is justified in believing, that his faculties are reliable” (p. 206). Tooley claims that on my position such a person would have a defeater for his belief that R … [But on my view] he has a defeater only if he has thought about this probability, and finds himself unable to say what it is.
Now, this initial response strikes me as odd. As I read Tooley, Tooley is saying that his subject has thought about it and has no bloody idea what P(R/T) is AND (this is the crucial bit) thinks it is intuitive to say that this subject does not have a defeater for his beliefs. But, to press the issue a bit, Plantinga goes on to say this:
By analogy, suppose you’ve just purchased a new sphygmomanometer; naturally enough, you assume that it is reliable. But now you learn that your sphygmomanometer was made in a factory owned by a Luddite who aims to create as much confusion as he can in the medical community, to that end by fashioning instruments a certain proportion of which are completely unreliable. You know this much, but you have no idea what that proportion is. Then the probability of your sphygmomanometer’s being reliable, given its origin, is inscrutable for you–and you certainly have a defeater for your initial belief that it is reliable (228)
I suppose Tooley might say this in response: I agree that you have a defeater for your beliefs about your blood pressure once you learn this new fact about the origin of the sphygmomanometer, but that’s quite different from the original scenario in which the subject had no specific reasons for doubting the reliability of his faculties.
Anyway, I do think there is an interesting issue here. Discuss.
Tooley’s second line of response is to argue that we should reject a crucial assumption in Plantinga’s argument if we assume a causal model of content. Recall that Plantinga’s argument assumes:
(7) If Darwinian evolution is true, then even if it is true both that neural states of type N are, in an organism H, reliable indicators of the presence of an instance of property P, and also that states of type N have content C, there is no reason why content C need to be related to property P.
[I]f a property-dualist, causal theory of content is correct, and if a neural, indicator state does give rise to syntactically structured experiential states in an appropriate way, then that neural state is belief. In addition, if the neural state is an indicator of the presence of a basic descriptive property of experiences, such as qualitative greenness, then the causal relation in question fixes the content of the neural state. Finally, given the satisfaction of a further condition related to indexicality, the content of the neural state is precisely the indexical belief that that’s an instance of qualitative greenness. It is therefore false, in the case of neural states that have content, that, “there is no reason why that content need be related to what the structures indicate, if anything”, since the content of any indexical belief about a basic observational/introspectible property of experiences logically supervenes upon the causal relation that makes it the case that the relevant neural state is a reliable indicator of the qualitative property in question (210).
That was a mouthful. In short, if we assume the causal theory of content that Tooley advocates we ought to reject (7) on the grounds that the conditions that determine the contents of our belief states will reliably lead us to the truth. The reliable connections between the indicators and the properties indicated will be part of the content-determining conditions for the relevant beliefs, so we have reason to think that such beliefs will likely prove to be correct. Assuming, that is, that the theory of content Tooley advocates is the correct one.
(i) Isn’t the claim that there is a necessary connection between the contents of beliefs and the properties indicated by the relevant reliable indicators “baseless”? (230)
(ii) If this account is extended to cover beliefs about things other than qualitative properties we can access through observation or introspection Tooley’s account succumbs to the “disjunction problem” (231).
(iii) There is no reason to think that under the conditions where a certain NP property causes adaptive behavior (e.g., by indicating the presence of a tiger) the belief that supervenes on these NP properties will have a content that is about a tiger because while, “the subvening properties must be adaptive … they can perfectly well do that no matter what the induced belief content (232).
Now, he’s aware that Tooley will say that on a causal theory of content the contents properly ascribed to the beliefs will depend (in part) upon what states of affairs stand in causal relations to the relevant NP’s. If that’s right, he might have to retract (iii). However, Plantinga says that the claim that the causal theory of content Tooley accepts is the correct one is baseless speculation:
Tooley merely assumes that the content of belief is fixed by causal relations, and, furthermore, so fixed that most beliefs will be true. That, it seems to me, is nothing like a successful response to the EAAN. It would be as if the theist responded to Tooley’s antitheistic argument by evil by simply postulating, without argument, that God has a good reason for permitting each of the evils the world displays. This proposition might be true … but merely postulating it isn’t much of a response to Tooley’s argument. I say the same holds for Tooley’s response to the EAAN.
At this point, I’m getting lost in the dialectic. First, I don’t think Tooley’s appeal to the causal theory of content is baseless. He presumably thinks that the causal theory is preferable to the intrinsic theory and thinks he has good reason for that preference. Maybe I’m missing something here, but I thought that there were good arguments for thinking that regardless of whether naturalism is true or not, the causal theories of content are preferable to the intrinsic theories. Why is it that Tooley can’t help himself to the causal theory? Second, if Tooley has shown that the EAAN only works if we insist that naturalism is not coupled with the causal theory of content Tooley prefers, I’d think this is a big setback. It’s not obviously irrational for a naturalist to accept that theory. It seems the best theory for the naturalist to adopt. If Plantinga is going to assert that naturalism is self-defeating, you’d hope that he’d argue that even if the naturalist helps herself to the best theory of thought content on the market the theory would still be self-defeating. It now seems that the complaint is not that the theory is self-defeating, but that a crucial aspect of it lacks external support. The naturalist will deny this, but that seems now to be where the action is.
As for (ii) I have to confess that I had a hard time understanding the significance of the disjunction problem in this context. (Maybe Plantinga is at this point just throwing everything including the kitchen sink at Tooley?) I thought that the disjunction problem was a problem for certain causal theories of content that took the content of a mental representation to be what caused tokens of that type of representation. If tokens were caused by, say, horses and zebras, how could there be beliefs that misrepresented the situation as one involving a horse when a zebra was present? Why wouldn’t the representation represent things as involving either a horse or zebra? While this is an interesting problem, why is this Tooley’s problem? Less determinate thought contents are less likely to be false than more determinate ones. (If every time you believe ‘That’s a horse’, I belief ‘That’s a horse or a zebra’, it’s more likely I’ll be right than you.) The disjunction problem is a problem for causal theories of content, not a problem for those who think that our beliefs will likely be true if that is the proper theory of content. This is a puzzling section.